1. Field of the Invention
The present invention relates to a blur correcting apparatus of a camera in which a blur correcting optical system is moved in a direction to reduce or eliminate a blur of an image in accordance with an output of a blur detector which detects the degree of blur caused by a camera-shake.
2. Description of Related Art
When a picture is taken by a camera which is held by a photographer hand or hands, if the photographer fails to stably or firmly hold the camera or takes a picture while moving or if an image of a dark object is taken at a slow shutter speed, the taken image tends to be blurred due to an accidental displacement of the optical axis of a photographing optical system, caused by a camera-shake, etc. during the period when the film is exposed. The resultant blurred image is dim and indistinct. The image blur can be attenuated to some extent. One hardware solution, is to use a bright lens or increase the film sensitivity to allow an increase in the shutter speed. A software solution would be to improve the photographer's skill at holding the camera more steady while taking the photograph.
To prevent the occurrence of the image blur, it is known that a camera can be provided with a blur correcting lens which is moved in a given direction to eliminate the image blur in accordance with an angular velocity (or angular acceleration) of the camera that represents the displacement of the optical axis of the photographing optical system caused by the camera-shake, using an angular velocity sensor (or angular acceleration sensor) of a camera, for example as proposed in Japanese Patent Application No. 4-192021 or Japanese Unexamined Patent Publication No. 62-44707). Namely, in this solution, the image is intentionally moved on a film surface in a direction opposite to the direction of the movement caused by the camera-shake to cancel the movement to eliminate the image blur.
In order to incorporate such a known blur correcting apparatus in a compact camera for example, it is necessary to realize a simple, compact and inexpensive structure of a blur correcting apparatus. However, if the camera or the blur correcting apparatus is to be made small, the correctable range of blur is inevitably reduced. Accordingly, if the shutter speed is set to be a slow speed or considerable camera-shake takes place, the correctable range of blur is sometimes too narrow to eliminate the blur.